Fitting aftermarket iPod adaptor

I'm no techie so would appreciate some help. I recently purchased the Xcarlink iPod adaptor. All seems sensible and straight-forward and I've got as far as working out how to get the radio out of the harness and which cables go where etc. The problem comes when I think about how to route the cable from the back of the radio down to the armrest box. This would seem to involve removing the centre console covers and it is at this stage that my nerve deserted me.

Alternatively, it looks as if it may be easier (although less satisfactory) to route the cable through to the glove box...

Has anyone else done this? Any tips, advice, guidance, help etc most welcome!

thanks
Peter